In recent years, rapid progress has been made in display technology. For example, thin film transistor (TFT) technology has been developed from original a-Si (amorphous silicon) TFTs to current LTPS (low temperature polysilicon) TFTs, MILC (metal-induced lateral crystallization) TFTs, oxide TFTs, and the like. Also, illumination technology has been developed from original LCDs (liquid crystal displays) and PDPs (plasma display panels) to current OLED (organic light-emitting diodes) and the like.
Currently, the oxide TFT has aroused increasing attention due to its various advantages. A TFT in which oxide semiconductor is used as an active layer has high mobility, good uniformity, transparency and better switching characteristics, and may also be applied to applications requiring prompt response and large current, such as a display with high frequency, high resolution and large size, an OLED display, and the like.
However, manufacturing process of an oxide TFT array substrate in the prior art is relatively complicated, and generally includes six photolithographic processes. FIG. 1 illustrates a schematic diagram of a typical structure of an existing oxide TFT array substrate, in which the oxide TFT array substrate includes a substrate 1, a gate 2, a gate insulation layer 3, an oxide active layer 4, an etching stop area 5, a drain 602, a source 601, a passivation layer 7 and a pixel electrode 8. For the oxide TFT array substrate with such a structure, six photolithographic processes are required to respectively form patterns including the gate 2, the oxide active layer 4, the etching stop area 5, the source 601 and the drain 602, a via in the passivation layer 7 and the pixel electrode 8. Therefore, the oxide TFT array substrate with such a structure has complicated manufacturing process and relatively high manufacturing costs.